1. Field of the Invention
The present invention relates to an original feeding method, and more particularly, it relates to an original feeding method used with an image forming system such as a copying machine, laser beam printer and the like.
2. Related Background Art
In the past, as a method for copying two images recorded on two originals on the same surface of a single sheet by using an original treating apparatus, a method for feeding two originals onto an original support glass in such a manner that the two originals are rested on the support glass side by side (referred to as "side-by-side reading mode" hereinafter) has been proposed, as disclosed in the Japanese Patent Laid-Open Nos. 60-2942, 60-84945, 60-93462 and the like.
By the way, as for the original treating sequence, when the originals are treated from a first page to a last page, in order to attain the page sequence, the originals and transfer sheets after treatment must be ejected with their image surfaces facing downwardly (face down), with the result that the visual check is worsened, leading to the delay of the discovery of disorder of pages and poor image. On the other hand, when the originals are treated from the last page to the first page, although the above problem can be solved, if the number of the originals is odd in the above-mentioned side-by-side reading mode, the first page of the transfer sheet after treatment (particularly, the left half of the first page) will be blank. In order to solve this problem, as disclosed in the Japanese Patent Laid-Open No. 62-55667, an odd selection button is provided in an operation portion so that, when the "odd" is selected by the odd selection button, only the image on the last page is transferred onto the single transfer sheet without using the side-by-side reading mode (of course, other pages are treated in the side-by-side reading mode), thus avoiding the blank portion on the first page of the transfer sheet.
However, in the above conventional technique (Japanese Patent Laid-Open No. 62-55667), there arise problems that an operator must judge whether the originals are odd or not and that, as can be seen from FIG. 26, since the originals are set with their image surfaces facing downwardly (face down), the desired copies cannot be obtained unless the operator carefully set the originals.
More specifically, although the originals should generally be set with their image surfaces facing downwardly so that the last page is an uppermost original, if the operator sets the originals upside down, when the copying operation is effected with a scan direction and a copy sheet convey direction as shown in FIG. 28, the wrong copy as shown in FIG. 27B will be obtained, contrary to the correct copy as shown in FIG. 27A. Unfortunately, the risk that the originals are set upside down will be increased, when they are set with their image surfaces facing downwardly, in comparison with the setting of the originals with their image surfaces facing upwardly.
Alternatively, with the arrangements as shown in FIGS. 26 and 28 wherein a side from which the original is introduced onto a platen (right side of these Figures) is opposite to a scan reference side (left side), since a distance between an original tray and the scan reference position is longer in a normal copy mode other than the side-by-side reading mode, it is hard to obtain the fast copy quickly. Nowadays, it is very important to reduce the copying time for the fast copy, in view of the high speed copying machine.
On the other hand, with the arrangement as shown in FIG. 29, since the original is introduced into the copying machine from the scan reference side (left side), the fast copy can be obtained quickly. However, since the originals are set on the platen as shown in FIG. 30 in the side-by-side reading mode, the left and right halves on the copy sheet are reversed, with the result that, when the copy sheet is folded in two and a plurality of copy sheets are stapled, the page sequence will be disordered. Further, as shown in FIG. 31, when the last page original is set on the platen at the scan reference side, the obtained copy sheet will be as shown, thereby generating the blank page between the last page and the previous page. Consequently, after the copy sheets are folded in two and are stapled, there arise blank pages in the stapled article.